Control system



G. E. YOUNG A 1,957.240

CONTROL SYSTEM Filed Nov. 16, 1931 Inventoh': George E.You.h g

His Attovngg.

with which is the index 6. I

turntable at the center thereof is the light source Patented May 1, 134

CONTROL SYSTEM George E. Young, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 16, 1931, Serial No. 575,494

2 Claims. ((11. 250-415) My invention relates to control systems and particularly to that type of control system which operates in response to the exposure to light of a photo-electric device. It is the object of my invention to provide an improved control system of the aforementioned type wherein the controlled element by its operation efiects a restoration of the original condition of light reaching the photo-electric device. I have chosen to illustrate my invention asapplied to the remote control of a searchlight which is rotatably mounted and provided with a driving motor :whereby the Searchlight may be turned through any desired angle in either direction under the control of an operator at a distant point.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its-scope will be pointed out in the appended claims.

In the single figure of the drawing which illustrates one embodiment of my invention, I have shown at l a rotatable support or turntable which by means of the shaft 2 and worm gearing 3' may be angularly adjusted by turning the crank 4. The turntable is preferably provided with graduations 5 around its periphery cooperating Mounted upon the '7 which may be a small incandescent lamp, and also mounted on me turntable, at points which are opposite each other or approximately so, are the two p devices may be of any desired type, such as selenium cells or photo-electric tubes. The latter, however, are preferred and are shown in the illustration. Secured to a separate shaft 12 rotatably mounted vcoarzially with the shaft 2 is the shield 13 which inthe form illustrated is substantially semi-cylindrical in form and is arranged to move between the light source '7 and one or the other of the devices 8 and 9. As so constructed and arranged the shield 13 intercepts light from the source '1 to one or the other of the photo-electric devices in accordance with the relative position or the shield and the turntable. The two devices 8 and 9 are connected through suitable amplifying devices 15 and. 1d.

a for example, electron discharge devices with the windings of, relays '17 and 18 respectively. The

contacts ofthese relays control respectively the windings of relays 19 and 20, energy for their operation being taken from the direct current circuit 21. Relays 19 and 20 are each provided with a double set 'of contacts and are so connected with the source 21 and with the control -electric devices 8 and 9. These circuit 22 that they function as a reversing switch. As a result of this arrangement while the photo-electric device 8 is exposed to light the current in the circuit v22 flows in .one direction, and while the other photo-electric device is exposed to light the current in the circuit 22 flows in the opposite direction. In the apparatus which I have chosen to illustrate my invention the control apparatus is shownas arranged to control the position of a searchlight. The searchlight 24 is mounted for rotary adjustment on a. vertical shaft and has the gear 25 secured thereto which is connected with the reversible motor 26 through suitable worm and spur gearing.

By the apparatus which I shall now describe, the angular adjustment of the Searchlight is caused to produce a corresponding angular movement of the shield 13 and as it is preferable to locate the control apparatus at a point which is distant from the searchlight, I employ electrical means for transmitting the movement of the searchlight to the shield. For this purpose I have shown a well known form of induction apparatus, known to the trade as a Sel'syn,'for transmitting the movements of the Searchlight. This apparatus is diagrammatically indicated as comprising the generator 27 and motor 28 both of which are of the same construction. As is well Mom with this form of apparatus the rotor of the motor follows exactly every angular movement of the rotor of the generator. The motor rotor is operatively connected, preferably directly connected, with the shaft 12 to which the shield is secured and the generator rotor is operatively connected, preferably by direct connection, with a shaft secured to gear 25 of the searchlight, or as shown in the drawing with shaft 29 which has a 1:1 gear connection with gear 25.

'With the apparatus as above described when it is desired to turn the searchlight to a different position, the turntable 1 is rotated an amount corresponding to the desired movement of the searchlight by the turning of the crank 4. Thus one of the photo-electric devices 8 and 9 will be exposed to light from the lamp 7, and through relay 17 or 18 as the case may be operates the appropriate relay 19 or 20 to cause the motor 26 to rotate in the proper direction to turn the Searchlight in the desired direction. As the searchlight turns, its movement is transmitted throughthe electrical means shown to the shield in the same direction that the turntable was turned. Thus the shield 13 is caused to follow up the movement of the turntable, and when the shield has moved through the same angular distance that the turntable was moved, it cuts on a the light from .the operating photo device thereby opening the circuit of the driving motor. The searchlight is thus brought to the angular position indicated by the control turntable and stopped. By suitable adjustments in the appara tus the Searchlight may be made to follow exactly every movement of the turntable and to come to rest in the exact position desired. If desired similar apparatus may be applied to control the movement of the Searchlight drum in the vertical plane. In certain cases I may prefer to operate the searchlight by adjusting the shield and cause the turntable to follow up the movement of the shield. I may also prefer to locate the control apparatus comprising the turntable,

shield, etc. at the Searchlight in which case the turntable -obviously may be mechanically connected with the searchlight, the shield being operated from a distant control point bythe Selsyn apparatus. The control system which I have disclosed as applied to a searchlight may be employed to operate various other apparatus, such for example as military guns or large wind T5 at airports.

I have chosen theparticular embodiment described above as illustrative of my invention and it will be apparent that various modifications may be made without departing from the spirit and scope of my invention which modifications I am to cover by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A control system comprising a light source,

a rotatable support, means for manually adjusting the angular position thereof, a plurality of photo-electric devices mounted thereon, a rotatable shield for said devices arranged to expose one or the other to the light from said source in accordance with the adjusted position of the support, a remote mechanism driven in one direction or the other in accordance with which one of said devices is exposed to the light and an electrical system for transmitting motion between said mechanism and said shield. whereby the shield automatically follows the adjusting movement of the support.

2. In asearchlight control system, a graduated turntable having a light source mounted centrallythereof and a plurality of photo-electric devices mounted thereon adjacent the periphery, means for adjusting the angular position of the turntable, a light shield rotatably mounted coaxially 'with said turntable and arranged to expose one or the other of said devices to light from said source, a reversible motor arranged to move the Searchlight, means'for causing the motor to rotate in one direction or the other in ac cordance with which one of said devices is exposed to light, and motion transmitting apparatus comprising a generator connected with the searchlight and a motor connected with the shield whereby the shield is caused to follow up the movements of the turntable.

GEORGE E. YOUNG. 

